A micro-light emitting diode (micro-LED) device includes semiconductor mesa structures, and waveguides and grating couplers in regions of a semiconductor layer between the semiconductor mesa structures. At least some light emitted in the active region of each semiconductor mesa structure can be coupled into and guided by a waveguide towards a grating coupler. The grating coupler is configured to diffract the guided light out of the micro-LED device, for example, in a direction substantially perpendicular to the light-emitting surface of the micro-LED device, through regions between the semiconductor mesa structures.